web engine breaks with Dart 3.0 #122724
Description
Web engine tests start failing when bumping the Dart SDK constraints to '>=3.0.0-0 <4.0.0' in these two files:
- https://github.com/flutter/engine/blob/bbde3a77b93528cf3f6b344ec80c3b800a8851d3/web_sdk/pubspec.yaml#L5
- https://github.com/flutter/engine/blob/bbde3a77b93528cf3f6b344ec80c3b800a8851d3/lib/web_ui/pubspec.yaml#L6
To see the failure, bump the Dart SDK to '>=3.0.0-0 <4.0.0' and run dev/felt test test/engine/pointer_binding_test.dart:
00:00 +30 ~1 -1: PointerAdapter does synthesize add or hover or move for scroll [E]
Expected: an object with length of <2>
Actual: []
Which: has length of <0>
org-dartlang-sdk:///lib/_internal/js_runtime/lib/js_helper.dart 1172:37 Object.wrapException
org-dartlang-sdk:///lib/_internal/js_runtime/lib/js_helper.dart 1203:25 Object.throwExpression
/.pub-cache/hosted/pub.dev/test_api-0.4.17/lib/src/expect/expect.dart 134:31 Object.fail
/.pub-cache/hosted/pub.dev/test_api-0.4.17/lib/src/expect/expect.dart 129:3 Object._expect
/.pub-cache/hosted/pub.dev/test_api-0.4.17/lib/src/expect/expect.dart 46:3 Object.expect
../../../../test/engine/pointer_binding_test.dart 988:7 testMain.<fn>
../../../../test/engine/pointer_binding_test.dart 33:9 _testEach.<fn>
/.pub-cache/hosted/pub.dev/test_api-0.4.17/lib/src/backend/declarer.dart 215:15 <fn>
org-dartlang-sdk:///lib/_internal/js_runtime/lib/async_patch.dart 308:19 _wrapJsFunctionForAsync.closure.$protected
org-dartlang-sdk:///lib/_internal/js_runtime/lib/async_patch.dart 333:23 _wrapJsFunctionForAsync.<fn>
Some initial investigation seems to indicate that synthesizing (or dispatching) scroll wheel events is somehow silently failing. Other mouse events seem to work. It is not clear what feature of dart 3.0 would cause this.